Abstract
Results and Conclusions
In Table I are summarized the number and type of “immunizing”injections administered and the number of survivors of 3 subsequent tumor implants given 1 month apart. The “immunizing”treatment in (1) and (2) killed over half of the animals, most dying of lymphoma, some of toxemia. The injections in (3) and (4) resulted in a mortality rate little more than would be expected in an untreated group in 4 months (9.5%). None developed tumors following injections of nuclei.
Of the 100 mice receiving a single injection of 500 viable lymphoma cells only 2 survived. Of these, one survived 2 implantations before succumbing to pneumonia and the other survived 3 implantations and at the time of this writing is still alive without tumor. Since the number of survivors is so small no deductions can be drawn regarding the efficacy of this treatment as means for “immunizing”the animals to the tumor. In group (2) receiving fragmented cells, 4 of the 43 survivors (9.3%) showed “immunity”to 3 successive implantations. Group (3) receiving tumor nuclei showed 2.4% “immunity”while in group (4) receiving liver nuclei there was 4.8% immunity.
Since no failures to “take”were observed in 2900 control animals inoculated with the tumor, the incidence of immune animals in this strain must be less than .035%. As a result of the treatments described, the incidence of immunity has been raised to 2.4–9.3% (which seems to be a significant increase). The injections of nuclei produce about as much “immunity”in this population of mice as the other two methods used (injection of viable and of ground frozen cells), without the risk of killing a large proportion of the animals entailed in these latter procedures. Furthermore the “immunization”obtained in treatments (3) and (4) must be attributed to a response to nuclear material only.
Get full access to this article
View all access options for this article.